There is a sensor module formed of a lens-integrated case provided with a dome-shaped lens unit and a cylindrical case unit extending downward from a lower end thereof, an attaching plate accommodated in the case unit, a circuit substrate accommodated in the case unit to be arranged below the attaching plate, a sensor fixed to an upper surface of the attaching plate, and a lower plate for blocking a lower-end opening of the case unit (refer to the patent document 1). In the sensor module, a plurality of terminals extending downward from the sensor penetrate the attaching plate, the circuit substrate, and the lower plate so as to protrude downward from the lower plate. The sensor is connected to the circuit substrate on a portion on which the terminal penetrates the circuit substrate. The circuit substrate converts an analog signal output from the sensor to a digital signal while amplifying the same. In the sensor module, the sensor fixed to the attaching plate and the circuit substrate are accommodated in a stacked manner in the lens-integrated case and the lower-end opening of the case unit is covered with the lower plate, so that they may be stored in the lens-integrated case and downsizing of the sensor module may be realized.